How do I add a HttpContextAccessor to the Starup.cs in the correct way. (ASP.NET Core 6)-CodePudding

So I'm trying to add a HttpContextAccessor to my startup.cs file and I find these two options.

services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
services.AddHttpContextAccessor();

So my question is, do I add both of them or just one? And what is the difference between them?

CodePudding user response：

The call to AddHttpContextAccessor uses TryAddSingleton, which will register the service only if it hasn't already been registered.

services.TryAddSingleton<IHttpContextAccessor, HttpContextAccessor>();

In your example, it has already been registered by that second call to services.AddHttpContextAccessor(), which means the next registration attempts do nothing.